The invention is based on a device and a method for monitoring the connection of an electrical supply unit. From German Patent DE 42 13443 C1, a circuit arrangement for monitoring the failure of fuses is already known. The fuses are each connected into the current paths of a rotary current network for supplying a consumer. The circuit arrangement has a first delta-connection circuit for detecting the phase of a voltage between each two conductors of the rotary current network upstream of the fuses and a second delta circuit for detecting the phase of a voltage between each two conductors of the rotary current network downstream of the fuses. The respective phases upstream and downstream of the fuses are compared with one another, and a failure signal is output if a phase difference occurs, or if one or more phases are absent. This circuit is also suitable for monitoring the connection of an electrical supply unit.
The object of the invention is to disclose a device for monitoring the connection which in particular reduces the requisite hardware expense for that purpose. This object is attained by the characteristics of the independent claim.